Logic/Conversion, inversion and contraposition
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Logic > Conversion, inversion and contraposition
Contents
- Category:Mathematical logic（Wikipedia）
- Propositional calculus
- Converse (logic)
- Inverse (logic)
- Contraposition (logic)
Overview
Definition of conversion, inversion and contraposition by truth table.
0 means false, 1 means true, and ≡ means equivalent.
If "P→Q" then its conversion is "Q→P", inversion is "￢P→￢Q" and contraposition is "￢Q→￢P".
| P | Q | P→Q | ￢P | ￢Q | Q→P：逆 | ￢P→￢Q：裏 | ￢Q→￢P：対偶 |
|---|---|---|---|---|---|---|---|
| 0 | 0 | 1 | 1 | 1 | 1 | 1 | 1 |
| 0 | 1 | 1 | 1 | 0 | 0 | 0 | 1 |
| 1 | 0 | 0 | 0 | 1 | 1 | 1 | 0 |
| 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 |
